In the review of the Sony A99 Nick Devlin makes a very interesting point.

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My view is that there is nothing inherently good about EVFs. They are at best a necessary evil, chosen for the form-factor advantages they bring and the cameras they make possible. Sony clearly does not share this view, since they built this camera around an EVF simply for the sake of doing so. It offers no notable advantage of any sort, most notably not in price. I can see no reason to chose an EVF in any context where it does not significantly reduce the size, weight or price of the camera, or substantially enhance its usability. The case is simply not made out beyond, "It's cool new technology".

To me, the experience of viewing the natural world through an EVF is like crashing at a cheap motel, closing the blinds, and turning on the small, fuzzy old cathode-ray tube TV on the dresser. It's a shame, because this is otherwise a cracker of a camera, really nice to hold and behold. – Nick

I would like to know what the other opinions are on the subject ? Some say that EVF's, as noisy as they are in the dark, let you focus on things that your naked eye can't see. That must surely be a benefit, right ?

In the review of the Sony A99 Nick Devlin makes a very interesting point.

I would like to know what the other opinions are on the subject ? Some say that EVF's as noisy as they are in the dark let you focus on things that your naked eye can't see. That must surely be a benefit, right ?

Agreed. I switch between them on the X100 regularly, but I sure do prefer the OVF. I switch because the EVF allows me to see more accurate framing and focus.

What this discussion misses is that the mirror-box on SLR cameras brought a bunch compromises with it. Why are Leica lenses so small and of such superb quality? Clue: it has something to do with the rear element being a lot closer to the film.

So...why are we suffering the disadvantages of the SLR mode if we gain none of the benefits? If you're using a pure EVF camera, then we should have the RF set of advantages, no?

Electronic screens in the open like all on-back LCD's are great, even more, a godsend. But EVF's are claustrophobic. I had briefly a Panasonic G3 and I sold it soon because the EVF gave me a sensation of being blinded, sort of seeing a video about soldiers using night vision devices in the front. I've never experienced this sensation while using an OVF, even in the darkest spots.In my opinion, I think it is still a long way till EVF's replace OVF's in dslr's, at least in FF. Further more, it may never happen entirely.Eduardo

I guess I'll be the voice of dissent. I started with the VF-2, the EVF accessory that showed up with the Olympus EP-2. I loved the fact that the EVF showed a much more realistic representation of what I would get in the final electronic file on my computer. Yes, the OVF is a lovely view but it's not what you get in the files, not even close. When the Sony a77 came out I bought a couple and a rash of lenses and I coined the phrase "pre-chimping." You get to tune in the colors and the exposure while you are shooting, eliminating the post chimping at waist level stage. My exposures are more accurate, my colors better matched now. I understand that I'm seeing an electronic representation but it's a representation that is much closer to what the final file WILL look like in the computer. The OVF is like being courted by a beauty and then ending up with the ugly sister after the fact.

I'm 56 and I cut my teeth on Hasselblad finders, Contax RTS cameras, R series Leicas and F5 Nikons and I'll admit in a minute that it's fun to have looked through all of those brilliant finders. But it's more efficient and surer to see what, in the ballpark, your files will look like without having to pull the camera from your eye while shooting. The Sony EVFs are really good. And this is how video artists have been working for years.

If you believe that you can Pre-visualize what you will end up with while looking through an OVF then you should be even better able to previsiualize what you'll get through an EVF because it's lightyears closer to the actual output. The EVFs are great, highly useable and only getting better and better.

Funny that Michael can see the benefit in the Sony Nex 7 but is emotionally stymied by the IDEA of full frame to such an extent that he can't overlay the same fluidity he's capable of with the 7 onto the a99. But everyone is different. I suggest you try one for yourself.

Look at an a77 finder. It should be close to the view you'll see in the a99. If it works for you it works. If you don't like it then I'll suggest it might be time for a system change...

I suppose I am another voice of dissent. For someone who likes to use manual focus lenses the OVFs of modern DSLRS are not exactly optimal. An EVF with focus peaking and image magnification, on the other hand, makes using those lenses extremely straightforward. In fact, the EVF is the main (only?) feature of the A99 which makes it an attractive alternative to my Nikon gear for me.

I prefer the G1 and its EVF to the 5D and its OVF in good and low light. In low light, lower than which would allow AF to lock on, the EVF allows me to focus on things with more accuracy than I can with the 5D but as the light level drops lower to night out of town levels my EVF blacks out and will not display things which are still clearly visible by eye and at these levels things can still be seen through the 5D's OVF, framing is much more accurate because you can see things and focus can be done by distance.

The only real downside I see to my G1's EVF are its inability to show detail when shooting at night and the fact that in low light the EVF acts like a torch shining directly into my eye destroying night vision and being extremely uncomfortable to use. If they could fix that I'd be very happy. There is a slight lag between reality and EVF but it's not an issue for me.

I quite like the G1 and I find that despite having a lower dynamic range than the 5D I'm less likely to blow the highlights or get the shadows too dark with the G1 as the in view histogram and WYSIWYG are great and of course there's no mirror slap and I find that I can hand hold at much lower shutter speeds than I can with the 5D, 25mm with whatever aperture and shutter speed I get on MFT allowing faster shutter speeds and / or lower ISO settings than equivalent settings with a 5D and 50mm.

I've seen examples of that on Gen1 of the SLT (Alpha 33/55). Not on Gen2 and Gen3.

Do you have any controlled tests from anywhere on the net taken with / without the removal of the mirror (it is easy to remove FWIW).

The grin was included specifically because there has been no real mention, much less examination of this issue. Common sense tells us there is *some* impact. Whether it is material is, as best as I can tell, unknown at this point.

The only real downside I see to my G1's EVF are its inability to show detail when shooting at night

This could be much improved with a simple firmware upgrade : on my rebel T1i, with the MagicLantern add-on firmware, I can decrease the live view refresh rate up to 0.2fps (ie 5s/image) so that each LV image is bright and clear (as a long exposure), even allowing manual focusing. Of course, it only works on a tripod, but for night photography that is a non-problem.

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and the fact that in low light the EVF acts like a torch shining directly into my eye destroying night vision and being extremely uncomfortable to use.

I agree. Using the LCD screen is less blinding, and moreover it's more comfortable on a tripod. I'd think of adding a red filter to the LCD...

There is also a classical side-effect : by simply reviewing the image on the LCD in obscurity, but not paying attention to the histogram, you'd think the shot is well exposed whereas it is several EV underexposed.

EVF anticipation remembers many years ago religious wars between rangefinder window-style and reflex finders.People, who use RF says that yo can see 'real world' image without and lag and blackout when shooting and all such similar words.But future was designed by and for reflex finders.Same with EVFs.

Unfortunately we cannot upgrade a99 finder in future, we'll have to buy a new camera.

Unlike video, still photography requires the photographer to keep changing from the viewfinder to real life and so on. LCD chimping is a mixture of both lights, no problem here. EVF's keep all natural light out, therefore blinding the photographer for seconds with its brighter than life view. EVF's may be great for video, not so much for still photography. Suffice to say this is for low light work. In very bright situations like open doors or at the beach, the opposite happens. I would really hate it if this world offered me cameras with evf's only. Eduardo

Agreed. I switch between them on the X100 regularly, but I sure do prefer the OVF. I switch because the EVF allows me to see more accurate framing and focus.

What this discussion misses is that the mirror-box on SLR cameras brought a bunch compromises with it. Why are Leica lenses so small and of such superb quality? Clue: it has something to do with the rear element being a lot closer to the film.

So...why are we suffering the disadvantages of the SLR mode if we gain none of the benefits? If you're using a pure EVF camera, then we should have the RF set of advantages, no?

To say nothing of the pellicle mirror degrading our micro-detail

- N.

I have found EVFs very useful when there is no other VF available, for example on some M43 cameras. I also like having some items such as the live histogram.

Overall though, I am not ready to move to an EVF only camera. maybe what I should say is that EVFs are not ready for me. They are improving, but for clarity, colour accuracy and overall connection to the scene I find OVFs superior - by far. While I have known this for a while, it became particularly clear when my Fuji enabled me to easily switch between the OVF / EVF. The EVF is very good and effective for what it is, but my VF of choice on the camera is the OVF.

I am in the market now for a new FF camera, and at this point am brand agnostic (I have passed on my L glass). The A99 has a great deal going for it, but the EVF, which is at the same level as that in the Nex 7, kills it for me.

The grin was included specifically because there has been no real mention, much less examination of this issue. Common sense tells us there is *some* impact. Whether it is material is, as best as I can tell, unknown at this point.

Actually the issue has been examined extensively.

There WAS an issue with the Gen1 SLT mirror (hair's breath slight increase in blur / also an offset slight reflectivity hotspot caused by secondary reflection from extreme bright points of light) but careful examination of the Gen2 and Gen3 SLT cameras has revealed no such issues. Sony's engineers fixed it.

Unlike mirror slap and first curtain shutter shake, which are entirely real phenomena which can be easily demonstrated and certainly cause image degradation, very significantly so under certain focal lengths and shutter speeds.

The bottom line is -- the SLT camera (and pure mirrorless as well) has some really important advantages, but it requires an EVF for framing. So if someone cannot stand to work with an EVF, then they will not like the new Sony Alphas.

So...why are we suffering the disadvantages of the SLR mode if we gain none of the benefits? If you're using a pure EVF camera, then we should have the RF set of advantages, no?

To say nothing of the pellicle mirror degrading our micro-detail

I tend to agree: previous Sony "SLT" cameras kept the mirror and its extra depth requirements for the sake of supporting PDAF, but now that Sony has that on the main sensor, it seems redundant. Maybe Sony is not yet confident that its in-sensor AF is as good as its traditional AF, but at most that seems a transitional "belt and suspenders" cautiousness.

So my guess is that the next step for Sony will be to abandon the reflex mirror entirely and make purely live view interchangeable lens cameras in 36x24mm format with a new lens mount, shallower that the Alpha SLR system's mount and probably different from the E-mount of the NEX system.

[EDIT: I retract the following, and the last sentence above, having seen photos of the NEX-VG900 video camera: the E-mount there clearly does avoid blocking any part of the 36x24mm sensor. The contacts extend inside part of the 42.5mm image circle, but avoid the corners of the 36x24mm frame, or close enough.]

Why not E-mount? From what I have read, at very least using that would not allow sensor-based stabilization, and I would expect Sony to provide sensor-based stabilization for the sake of being able to fully utilize all its non-stabilized alpha mount lenses via an adaptor. Actually, I suspect that E-mount would also cause some vignetting at low f-stops, due to having an opening of only 39mm in diameter 12mm from the focal plane, smaller than the 42mm diameter of the 36x24mm sensor. The chief rays would reach the sensor, but not all the rays towards the outer edge of the light cone with a low f-stop.

Nick Devlin says of the Sony A99:I tend to agree: previous Sony "SLT" cameras kept the mirror and its extra depth requirements for the sake of supporting PDAF, but now that Sony has that on the main sensor, it seems redundant. Maybe Sony is not yet confident that its in-sensor AF is as good as its traditional AF, but at most that seems a transitional "belt and suspenders" cautiousness.

So far, none of the on-sensor PDAF systems are anywhere near as good as traditional PDAF. Nikon's seems to be the best in bright light, but I suspect it benefits greatly from the increased DOF of the small sensor / short focal length lenses the system uses. In dim light, it shuts down completely and the camera relies only on CDAF. Canon's version, on both the T4i and EOS M seems pretty dismal. Sony's "belt and suspenders" approach leads me to believe that their version of on-chip PDAF doesn't solve the problem either.

As for the question of OVF vs. EVF, like most things in life, it's a matter of trade-offs. In good light, the OVF of a FF camera is much easier to view and compose on than today's best EVFs. And in theory, you could still do overlays of shooting information, histogram, etc. In dim light, though, the light amplification capability of an EVF can be a godsend, especially for those of us with aging eyesight. And EVFs offer the overlay of shooting data, histograms, overexposure / underexposure blinkies and other information today. EVFs also offer 100% coverage, which most OVFs don't. Oh, and no need for a eyepiece shutter when shooting on a tripod.

Step down from FF cameras, and the advantages of OVFs weaken a little. Step down to entry level DSLRs with their tiny, dim penta-mirror designs, and I'd give the advantage to the best of today's EVFs.

As others have pointed out, EVFs offer real advantages for manual focus and the ability to preview the actual exposure. OVF's are still superior for tracking rapid movement and high-speed burst shooting. But EVFs continue to improve. OVF's are pretty much as good as they're going to get. (Actually, in some ways they've regressed. The OVF on my old 35mm film cameras were better in many respects than on today's APS-C DSLRs. More contrasty for better MF, and useful DOF preview, and higher magnification.

Shooting sports or wildlife, give me a fast working DSLR with an good OVF. Shooting in dim light, I prefer an EVF. Trade-offs--no one's made the perfect camera yet.

The bottom line is -- the SLT camera (and pure mirrorless as well) has some really important advantages, but it requires an EVF for framing. So if someone cannot stand to work with an EVF, then they will not like the new Sony Alphas.

Unfortunately, there's a downside, too. (I like mirrorless, btw, and use a GH2 pretty extensively.) Since the shutter has to be open for viewing on the EVF, there's a double motion to take a photo: the shutter needs to close first, and then begin the exposure. Not only does this increase shutter lag, it seems to cause more vibration. There's a fair bit of empirical evidence that at certain shutter speeds increased camera shake is a problem, especially with some of the lighter bodies.

Unfortunately, there's a downside, too. (I like mirrorless, btw, and use a GH2 pretty extensively.) Since the shutter has to be open for viewing on the EVF, there's a double motion to take a photo: the shutter needs to close first, and then begin the exposure. Not only does this increase shutter lag, it seems to cause more vibration. There's a fair bit of empirical evidence that at certain shutter speeds increased camera shake is a problem, especially with some of the lighter bodies.